For example, in a PWM signal generation technique for a power converter, when a power converter is PWM-controlled, it is essential to add dead time to a PWM signal so as to prevent short-circuiting due to switching delay of a switching element connected in series between power sources. However, influence of dead time causes mismatch of an output voltage of the power converter with a voltage command value and distortion in a load current waveform.
Accordingly, as a method for compensating for the influence of dead time, many compensation methods such as a system where compensation of a preset compensation amount to a voltage command value is performed according to a load current polarity or a system where compensation is performed by feeding back an output voltage from the power converter have been proposed.
The system where compensation of a preset correction amount is performed generates an error due to a difference between a set correction amount and an operating speed of an actual switching element and the like, which results in impossibility of precise compensation. As the system for conducting compensation by performing feedback of an output voltage, a system realizing compensation by utilizing hardware (for example, Japanese Patent Application Laid-Open Publication No. 2000-312486 (Patent Document 1)) and a system realizing compensation by utilizing software (for example, Japanese Patent Application Laid-Open Publication No. 2001-352764 (Patent Document 2)) are known. Further, techniques disclosed in Japanese Patent Application Laid-Open Publication No. 2006-158064 (Patent Document 3) and the like have been proposed.